1. Field of the Invention
This invention relates in general to a hydraulic device incorporating a cylinder-piston assembly, and more particularly a double acting hydraulic device having at least two cylinder-piston assemblies which operate synchronously.
2. Description of the Prior Art
A device having a double acting cylinder-piston assembly is known from FR-A-2 380 218.
Because the effective piston surfaces are the same in the chambers mutually connected by the direct connection, the quantity of oil displaced from the one chamber will provide in the other chamber an equal displacement of the relevant piston. The valve means bring about a synchronous adjustment of the pistons at the end of each stroke. Any leakage of oil from the two chambers mutually connected by the direct connection would normally result in a nonsynchronous position of the pistons, although the movements continue to proceed at exactly the same speed. Use of the said valve means results in the oil that may be lost through leakage being supplemented via the bypass at the end of each stroke.
Due to the non-return valves oil under pressure can only be fed in one direction, in the shown embodiment in the direction in which the piston rod extend. The ingoing stroke occurs due to external force.